JP2003111359A - Method of manufacturing motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of manufacturing a motor composed of a permanent magnet rotor which can improve torque and efficiency, and to provide an annular permanent magnet forming mold which is most suitable for the manufacturing method. SOLUTION: An annular permanent magnet 2 of which the rotor of a motor is composed is formed by a mold in which a magnetic field orientation permanent magnet 1, which has a magnetic inner core 5 at a position in a part corresponding to the inner circumferential side of the annular permanent magnet 2, is provided together with a center core attached to at least one center core among nonmagnetic center cores (3a-3d) arranged vertically. With such a constitution, the orientation rate of the annular permanent magnet 2 can be improved, and the torque and efficiency can be improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a motor in which a ring-shaped permanent magnet used for a motor is magnetically oriented from the outside while a magnetic field is magnetically oriented.

[0002]

2. Description of the Related Art In recent years, DC brushless motors have been developed to meet the demand for energy saving of motors. In the DC brushless motor, since there is no rotor bar in the induction motor, there is no secondary copper loss, and high torque due to the strong magnetic force of the permanent magnet can be realized.

Conventionally, when a ring-shaped permanent magnet is molded, a non-magnetic material is used as the material of the mold parts around the molded product in order not to disturb the magnetic field orientation, so that there is no back yoke and the degree of orientation is weakened.

Further, Japanese Laid-Open Patent Publication No. 5-175037 discloses a magnetic circuit device of a magnetic field orientation molding die relating to a ring-shaped permanent magnet which is extremely anisotropically oriented, and an outer peripheral portion of the permanent magnet for magnetic field orientation. In which a back yoke made of a ferromagnetic material is arranged, and the magnetic material is arranged in a part of a portion corresponding to the inner peripheral side of the ring-shaped permanent magnet in the ring-shaped permanent magnet molding cavity. Has been done.

Further, in Japanese Unexamined Patent Publication No. 2000-324785, manufacturing in which a main magnetic pole portion in which the easy axis of magnetization of magnetic powder is polar-oriented and a shaft are integrally molded in a mold containing a magnet for magnetic field orientation The method is described.

[0006]

In the above structure, when it is necessary to increase the amount of magnetic flux of the rotor in order to improve the torque and efficiency, the product thickness is increased or the material of the ring-shaped permanent magnet is changed to the residual magnetic flux density. There are methods such as using a high one, or using a permanent magnet for magnetic field orientation having a high residual magnetic flux density.

However, since these materials use a large amount of materials, there is a problem that the material cost becomes high and the motor becomes large in size.

Further, when the die structure is such that the back yoke made of a ferromagnetic material is arranged on the outer peripheral portion of the permanent magnet for magnetic field orientation, it is necessary to assemble the permanent magnet for magnetic field orientation in the back yoke with high precision. It was difficult to assemble a permanent magnet for magnetic field orientation that has strong magnetic properties.

Further, there is a case where an iron-based material which is a magnetic material is adopted as the shaft material, but in general, the diameter of the shaft is considerably smaller than the outer diameter of the ring-shaped permanent magnet. Since the distance from the surface of the magnet for magnetic field orientation to the surface of the shaft becomes long, the shaft could not function as a yoke during magnetic field orientation.

The present invention has been made in view of the above problems, and a method for manufacturing a motor having a permanent magnet rotor as a constituent element capable of improving torque and efficiency, and a ring-shaped permanent magnet molding suitable for the manufacturing method. The purpose is to provide a mold.

[0011]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention attaches a ring-shaped permanent magnet constituting a rotor of a motor to at least one of cores made of non-magnetic material arranged above and below. The ring-shaped permanent magnet and the ring-shaped permanent magnet are molded in a mold that houses a magnet for magnetic field orientation in a part of the inner peripheral side of the ring-shaped permanent magnet. The degree of orientation of the permanent magnet can be increased, and the torque and efficiency can be improved.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION The invention according to claim 1 of the present application is
In a method of manufacturing a motor comprising a ring-shaped permanent magnet rotor and a stator having magnetic field orientation-molded permanent magnets in a mold, the ring being in the ring-shaped permanent magnet molding cavity of the mold, In the state in which a magnetic body is arranged in a part in the axial direction of a portion corresponding to the inner peripheral side of the ring-shaped permanent magnet, and a core made of a non-magnetic body is arranged above and below the magnetic body, the ring-shaped permanent magnet is A method for manufacturing a motor characterized by being molded, in which a magnetic core disposed near the magnetic field orientation magnet (a position corresponding to the inner peripheral surface of the ring-shaped permanent magnet) is installed outside the magnetic field. It serves as a back yoke for the permanent magnet for orientation, and can enhance the degree of orientation of the ring-shaped permanent magnet. Furthermore, the magnetic rotor core or magnetic core is placed in the portion of the ring permanent magnet where the magnetic force is most desired to be increased. It is possible to improve the torque and efficiency Rukoto.

According to a second aspect of the present invention, a portion corresponding to the inner peripheral side of the ring-shaped permanent magnet is provided with the core attached to at least one of the cores made of non-magnetic material arranged above and below the magnetic material. According to the method for manufacturing a motor of claim 1, wherein the magnetic body is arranged in a part of the magnetic body, the magnetic body can be arranged with high accuracy, and the arrangement is easy.

According to a third aspect of the present invention, after the ring-shaped permanent magnet is molded, demagnetization is performed, and then the assembly is performed, so that the motor according to any one of the first and second aspects is assembled. This is a manufacturing method, and the workability of assembly can be improved by demagnetizing the ring-shaped permanent magnet rotor after molding and hardening, and then inserting the magnetic rotor core.

The invention according to claim 4 is the method for manufacturing a motor according to claim 1, characterized in that the magnetic material disposed between the cores made of a non-magnetic material is a rotor core.
Since the rotor core and the ring-shaped permanent magnet are integrally formed, the number of steps for assembling the motor can be reduced.

According to a fifth aspect of the present invention, the magnetic field orientation in the mold is a polar anisotropic orientation, and the motor manufacturing method according to any one of the first to fourth aspects. Therefore, the magnetic force of the ring-shaped permanent magnet can be increased, and the magnetic flux distribution on the surface can be sinusoidal.

According to a sixth aspect of the present invention, there is provided a die for molding a ring-shaped permanent magnet of a ring-shaped permanent magnet rotor, wherein the ring-shaped permanent magnet is inside the ring-shaped permanent magnet forming cavity of the die. A central core made of a non-magnetic material, which is vertically divided into two parts, and a central core made of a magnetic material, which is fixed to at least one of the vertically divided two parts of the central core, and A ring-shaped permanent magnet molding die, characterized in that a magnetic field orientation magnet provided in a magnetic field orientation permanent magnet holder made of a non-magnetic material is housed in the outer periphery of the cavity inside the die. Therefore, the assembly of the mold including the mold maintenance is facilitated, and the degree of orientation of the ring-shaped permanent magnet can be increased.

[0018]

EXAMPLES Specific examples of the present invention will be described below with reference to FIGS.

(Embodiment 1) FIG. 1 is a cross-sectional view of a mold for molding a ring-shaped permanent magnet, and FIG. 2 is a plan view of a mold for molding a ring-shaped permanent magnet. There is.

As shown in FIG. 1, the magnetic field orientation permanent magnet 1 housed inside the mold is disposed outside the ring-shaped permanent magnet 2 and compared with the height of the ring-shaped permanent magnet 2.
It has the same or higher height.

The magnetic field orientation permanent magnet 1 is arranged on the circumference of the ring-shaped permanent magnet 2 (see FIG. 2). By increasing the thickness of the ring-shaped permanent magnet 2, a polar anisotropic orientation is obtained. Become. Further, during molding, the magnetic core 5 serves as a back yoke to increase the degree of orientation, and as a result, torque and efficiency can be improved without increasing cost.

The materials of the mold components are the upper center core, the lower center core, the upper mold plate 3e, the lower mold plate 3f, and the magnetic field alignment so as not to disturb the magnetic field alignment when molding the ring-shaped permanent magnet 2. The permanent magnet holder 3g is a non-magnetic material, and the upper core is composed of the upper mold core 3a and the upper mold core 3b, and the lower central core is composed of the lower mold core 3c and the lower mold core 3d. There is.

Further, it is desirable to use a non-magnetic material as the material for the bolts and the like for mounting the mold component parts. However, even for the magnetic material bolts, the effect is small, and if not particularly necessary, this point should be taken into consideration. You don't have to.

On the other hand, the magnetic core 5 is a magnetic core and is fixed to the lower mold core 3d by bolts or the like.
The bolt at this time may be a magnetic material.

Although the actual die structure is more complicated, the details are drawn in a simplified manner.

The manufacturing process will be described below.

First, the mold is closed and the material of the ring-shaped permanent magnet 2 is poured. The mold temperature at this time is in the range of 40 to 150 degrees, and the set temperature is a temperature at which the material of the ring-shaped permanent magnet 2 flows and the magnetic field orientation permanent magnet 1 is not demagnetized.

After the material of the ring-shaped permanent magnet 2 is filled in the mold, it is cooled to cure the ring-shaped permanent magnet 2.

At the time of molding, the magnetic core 5 serves as a back yoke to increase the degree of orientation and, as a result, torque and efficiency are improved.

Thereafter, as shown in FIG. 3, the ring-shaped permanent magnet 2 and the magnetic rotor core 4 are assembled.

FIG. 4 is a sectional view of the ring-shaped permanent magnet 2 of the present invention molded in FIG. 1, and the ring-shaped permanent magnet 2 and the magnetic rotor core 4 are fixed by an adhesive 6.

By fixing the magnetic rotor core for fastening the ring-shaped permanent magnet and the shaft after cooling with the adhesive 6, for example, a difference in linear expansion coefficient between the ring-shaped permanent magnet 2 and the rotor core, which occurs during integral molding. The internal stress due to can be minimized.

Here, the rotor core 4 does not necessarily have to be a magnetic body, but it is desirable that the rotor core 4 has substantially the same size as the magnetic core 5 and is made of a magnetic material.

The rotor manufactured in this manner is assembled so as to be rotatably held by the bearing with respect to the stator, and becomes a completed motor product.

The ring-shaped permanent magnet 2 and the magnetic core 5 are used.
If the axial heights of the ring-shaped permanent magnets 2 are the same, both ends of the ring-shaped permanent magnet 2 are likely to have radial orientation. It is necessary to dispose the magnetic core 5 in the portion.

Furthermore, in the above description, the magnet for orienting the magnetic field is a permanent magnet, but the same effect can be obtained even when it is an electromagnet.

(Embodiment 2) FIG. 5 is a sectional view of a mold for molding a ring-shaped permanent magnet, and FIG. 6 is a plan view of a mold for molding a ring-shaped permanent magnet. There is.

As shown in FIG. 5, the magnetic field orientation permanent magnet 1 housed inside the mold is arranged outside the ring-shaped permanent magnet 2 and is compared with the height of the ring-shaped permanent magnet 2.
It has the same or higher height.

Further, the magnetic field orientation permanent magnet 1 is arranged on the circumference of the ring-shaped permanent magnet 2 (see FIG. 6), and by increasing the thickness of the ring-shaped permanent magnet 2, it becomes a polar anisotropic orientation. Become. Further, during molding, the magnetic rotor core 4 serves as a back yoke to increase the degree of orientation, and as a result, torque and efficiency can be improved without increasing cost.

The materials of the mold components are the upper center core, the lower center core, the upper mold plate 3e, the lower mold plate 3f, and the magnetic field alignment so as not to disturb the magnetic field alignment when molding the ring-shaped permanent magnet 2. The permanent magnet holder 3g is a non-magnetic material, and the upper core is composed of the upper mold core 3a and the upper mold core 3b, and the lower central core is composed of the lower mold core 3c and the lower mold core 3d. There is.

Further, it is desirable to use a non-magnetic material as the material for the bolts and the like for mounting the mold component parts, but even for the magnetic material bolts, the effect is small, and if not particularly necessary, this point should be considered. You don't have to.

Although the actual mold structure is more complicated, the details are drawn in a simplified manner.

The manufacturing process will be described below.

First, the magnetic rotor core 4 is placed in a mold by a machine or an operator's hand. At this time, it is desirable to preheat the magnetic rotor core 4 before insertion to the same temperature as the mold.

At this time, the shaft hole or the positioning hole of the magnetic rotor core 4 is used for positioning the magnetic rotor core 4.

Next, the mold is closed and the material of the ring-shaped permanent magnet 2 is poured. The mold temperature at this time is in the range of 40 to 150 degrees, and the set temperature is a temperature at which the material of the ring-shaped permanent magnet 2 flows and the magnetic field orientation permanent magnet 1 is not demagnetized.

The material of the ring-shaped permanent magnet 2 is filled in a mold and then cooled to cure the ring-shaped permanent magnet 2.

Finally, the ring-shaped permanent magnet 2 is taken out from the mold and the process is repeated.

In the above description, the ring-shaped permanent magnet 2 is formed integrally with the magnetic rotor core 4.

FIG. 7 shows a ring-shaped permanent magnet rotor integrally molded according to FIG. 5, and the ring-shaped permanent magnet 2 and the magnetic rotor core 4 are integrally molded and fixed.

The rotor manufactured in this manner is assembled so as to be rotatably held by the bearing with respect to the stator, and becomes a completed motor product.

The ring-shaped permanent magnet 2 and the rotor core 4 are
When the axial heights of the two are the same, radial orientation is likely to occur at both end portions of the ring-shaped permanent magnet 2, so the laminated thickness of the rotor core 4 should be lower than the height of the ring-shaped permanent magnet 2.

Further, in the above description, the magnet for orienting the magnetic field is a permanent magnet, but the same operational effect can be obtained even when it is an electromagnet.

[0054]

As described above, according to the invention described in the present application,
When molding the ring-shaped permanent magnet, a magnetic body is arranged in a part of the ring-shaped permanent magnet molding cavity of the mold in the axial direction of a portion corresponding to the inner circumferential side of the ring-shaped permanent magnet, and With the cores made of non-magnetic material placed above and below the magnetic material, the magnetic field was oriented in the mold so as to achieve the anisotropic orientation, and the ring-shaped permanent magnet was formed. Is a back yoke of the permanent magnet for orientation installed on the outside, and a method of manufacturing a motor capable of increasing the degree of orientation can be realized. The motor manufactured by the method can improve the torque and efficiency as the amount of magnetic flux increases.

Further, by arranging the magnetic material in the portion of the ring-shaped permanent magnet where the magnetic force is most desired to be increased, the magnetic center of the ring-shaped permanent magnet can be arbitrarily changed to improve the torque and efficiency of the motor. be able to.

Further, by arranging the above-mentioned magnetic body in a core structure attached to at least one of cores made of non-magnetic material arranged above and below the magnetic body, the magnetic body can be accurately arranged. It is possible to realize a motor manufacturing method that is capable of providing a highly reliable motor with little variation in characteristics.

Further, by making the magnetic field orientation of the ring-shaped permanent magnet extremely anisotropic, the magnetic force of the ring-shaped permanent magnet is strengthened, and since the magnetic flux distribution on the surface becomes sinusoidal, vibration and noise can be reduced. it can.

Further, the mold structure has a core which is made of a non-magnetic material and which is divided into two parts in the ring-shaped permanent magnet molding cavity in a portion corresponding to the inner peripheral side of the ring-shaped permanent magnet.
A permanent core for magnetic field orientation, which comprises a magnetic core fixed to at least one of the upper and lower split cores, and which is the outer peripheral portion of the cavity inside the mold and is made of a non-magnetic body. By accommodating the magnetic field orientation magnet provided in the magnet holder, the assembly of the die including the die maintenance becomes easy, and the degree of orientation of the ring-shaped permanent magnet can be increased.

[Brief description of drawings]

FIG. 1 is a sectional view of a ring-shaped permanent magnet molding die according to a first embodiment of the present invention.

FIG. 2 is a plan view of a ring-shaped permanent magnet molding die described in Example 1 of the present invention.

FIG. 3 is a schematic view showing a method for manufacturing the ring-shaped permanent magnet rotor according to the first embodiment of the present invention.

FIG. 4 is a cross-sectional view of the ring-shaped permanent magnet rotor according to the first embodiment of the present invention.

FIG. 5 is a sectional view of a ring-shaped permanent magnet molding die according to a second embodiment of the present invention.

FIG. 6 is a plan view of a ring-shaped permanent magnet molding die according to a second embodiment of the present invention.

FIG. 7 is a sectional view of a ring-shaped permanent magnet rotor according to a second embodiment of the present invention.

[Explanation of symbols]

1 Permanent magnet for magnetic field orientation 2 Ring-shaped permanent magnet 3a, 3b Upper core 3c, 3d Lower core 3e Upper mold plate 3f Lower template 3g Permanent magnet holder for magnetic field orientation 4 Magnetic rotor core 5 Magnetic core

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Shinkichi Odawara             1006 Kadoma, Kadoma-shi, Osaka Matsushita Electric             Sangyo Co., Ltd. F-term (reference) 5H622 AA03 CA02 CA06 CA14 CB03                       CB04 QA02

Claims (6)

[Claims] 1. A method for manufacturing a motor comprising a ring-shaped permanent magnet rotor and a stator, which comprises a permanent magnet magnetic field orientation-molded in a mold, in a ring-shaped permanent magnet molding cavity of the mold. In the state where the magnetic body is arranged in a part of the portion corresponding to the inner peripheral side of the ring-shaped permanent magnet in the axial direction, and the core made of a non-magnetic body is arranged above and below the magnetic body, A method for manufacturing a motor, wherein a ring-shaped permanent magnet is molded. 2. A magnetic core, which is attached to at least one of nonmagnetic cores disposed above and below a magnetic core, and a part of a portion corresponding to the inner peripheral side of the ring-shaped permanent magnet. The method for manufacturing a motor according to claim 1, wherein the motor is arranged. 3. The method for manufacturing a motor according to claim 1, wherein the ring-shaped permanent magnet is molded, and then demagnetized, and then assembled. 4. The method for manufacturing a motor according to claim 1, wherein the magnetic body disposed between the cores made of a non-magnetic body is a rotor core. 5. The method of manufacturing a motor according to claim 1, wherein the magnetic field orientation in the mold is a polar anisotropic orientation. 6. A ring-shaped permanent magnet molding die for a ring-shaped permanent magnet rotor, the portion corresponding to an inner peripheral side of the ring-shaped permanent magnet in the ring-shaped permanent magnet molding cavity of the die. The cavity formed of a non-magnetic material and having a vertically divided core and a magnetic core fixed to at least one of the vertically divided core and having the cavity inside the mold. A ring-shaped permanent magnet molding die, which houses a magnet for magnetic field orientation provided in a permanent magnet holder for magnetic field orientation made of a non-magnetic material in an outer peripheral portion.